Cross-adjustment rate control circuit and method for multi-output power

Abstract

The invention relates to a cross-adjustment rate control circuit and method for a multi-output power, belongs to the technical field of cross-adjustment rate control and aims to solve problems of low efficiency and low main-output voltage accuracy in the prior art. The circuit includes a multi-output power, a coupling inductor L1 and a feedback control circuit, wherein the multi-output power includes an input power Uin, a main output Vo1 and a secondary output Vo2, the coupling inductor L1 is connected between the main output Vo1 and the auxiliary output Vo2 and is used for regulating an output voltage of the main output Vo1 according to an output voltage of the auxiliary output Vo2, the feedback control circuit includes a PI controller and a PWM generator, the PI controller is used for receiving the output voltage of the main output Vo1 as a feedback signal and regulating the PWM generator to output a PWM signal having a corresponding duty ratio and further controlling the input power Uin for supplying power for the multi-output power. The circuit is advantaged in that indirect closed loop control of the secondary output Vo2 is realized, and the output voltage control effect of the secondary output is improved.

Description

technical field [0001] The invention relates to the technical field of cross regulation rate control, in particular to a cross regulation rate control circuit and method of a multi-channel output power supply. Background technique [0002] For a multi-output flyback switching power supply using a multi-winding transformer, one of the outputs is usually selected as the main output for output voltage feedback adjustment, and the other outputs are used as auxiliary outputs. Ideally, the main output voltage and auxiliary output voltage meet the turn ratio relationship of the corresponding windings of the transformer. As long as the main output voltage is kept stable, the auxiliary output voltage can also be kept stable according to a certain ratio. However, due to the leakage inductance between transformer windings and other reasons in actual situations, the voltage of the auxiliary output will not only change with the change of its own load, but also change with the load of oth...

AI Technical Summary

Problems solved by technology

[0006] In view of the above analysis, the present invention aims to provide a multi-channel output power supply cross-regulation rate control circuit and method to solve the problems of high power consumption, low efficiency and low output voltage accuracy of the existing multi-channel output power supply cross-regulation rate method. question

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